[PATCH 17/20] perf tests: Do not assume that readlink() returns a null terminated string

[Arnaldo Carvalho de Melo]

From: Tommi Rantala <tommi.t.rantala@xxxxxxxxx>

Ensure that the string in buf is null terminated.

Signed-off-by: Tommi Rantala <tommi.t.rantala@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170322130624.21881-4-tommi.t.rantala@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/tests/sdt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/sdt.c b/tools/perf/tests/sdt.c
index f59d210e1baf..26e5b7a0b839 100644
--- a/tools/perf/tests/sdt.c
+++ b/tools/perf/tests/sdt.c
@@ -43,7 +43,7 @@ static char *get_self_path(void)
 {
 	char *buf = calloc(PATH_MAX, sizeof(char));
 
-	if (buf && readlink("/proc/self/exe", buf, PATH_MAX) < 0) {
+	if (buf && readlink("/proc/self/exe", buf, PATH_MAX - 1) < 0) {
 		pr_debug("Failed to get correct path of perf\n");
 		free(buf);
 		return NULL;
-- 
2.9.3